JP2007336711A - Digital protection relay incorporating phase control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital protection relay incorporating a phase control in which a phase control system can be achieved by processing the input signal of a present digital protection relay. <P>SOLUTION: The digital protection relay 1 incorporating a phase control used for interrupting and closing a circuit breaker 90 provided at each phase of a transmission/distribution line comprises a phase control determination circuit 32 which calculates a zero-point time t<SB>zero</SB>, a residual time T and a waiting time T0 at a predetermined time for a plurality of current signals I<SB>a</SB>, I<SB>b</SB>and I<SB>c</SB>representing current values of respective phases of the transmission/distribution line inputted externally, and a phase control sequence processing circuit 42 which delivers an output signal so that the interruption signal of a switchgear is outputted at a time t<SB>2</SB>when a waiting time T0<SB>1</SB>calculated by the phase control determination circuit 32 has elapsed after a time t<SB>1</SB>when a fault occurrence signal or an interruption designation signal has been inputted for at least one phase of the transmission/distribution line. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a digital protection relay device with a built-in phase control, and more particularly, to a digital protection relay device with a built-in phase control suitable for reducing deterioration and damage of a contact portion due to an arc when a power system switching device is shut off.

  Conventionally, in order to reduce deterioration and damage of contact parts due to arcs when opening and closing a power system switchgear (for example, circuit breaker), the timing at which the AC current reaches the zero point is predicted from the current and voltage phase of the circuit Thus, a control method for opening and closing the contact portion (hereinafter referred to as “phase control method”) has been proposed.

  In order to realize such a phase control method, in the phase control switching device disclosed in Patent Document 1 below, the current value or current gradient value of the current to be opened / closed by providing a current measurement unit or current gradient measurement unit is obtained. Measure and predict the current zero point of the current waveform from the measured value by the reference phase detector, and control the opening phase control operation based on the arbitrary time after the current waveform prediction by receiving the switching pole command of the circuit breaker By controlling the switching timing of power switchgears, it is possible to suppress the occurrence of exciting inrush currents and switching surge voltages that are severe for system equipment such as transformers, reactors and capacitor banks, and The time is controlled and the circuit breaker is operated at the arc time when the arc does not recur and the optimum breaking time is used to cut off.

In addition, in the power switching control device disclosed in Patent Document 2 below, an operation time prediction unit that predicts fluctuations in the switching time of the power switching device, and at least one of the main circuit voltage and the main circuit current of the power switching device A phase detection unit that detects the phase of the switch, and a phase in which the predicted phase of the switching pole is added to this phase with reference to a predetermined phase detected by the zero point detection unit when a switching pole command is input to the power switchgear. And a control signal generation unit that outputs a power switchgear opening / closing pole command to the power switchgear so that the power can be turned on or off at a desired timing.
JP 2000-188044 A JP 2001-057135 A

  However, in the conventional phase control system, since a detection / control circuit attached to the switchgear is provided or a control device is provided separately from the switchgear, a special switchgear such as a switchgear of the phase adjusting equipment is provided. However, there is a problem that the cost increases when it is used in a normal switchgear.

  An object of the present invention is to provide a digital protection relay device with built-in phase control that can realize a phase control method by processing an input signal of a current digital protection relay device.

The digital protection relay device with built-in phase control according to the present invention is a digital protection relay device with built-in phase control (1) used for shutting off and turning on a switching device (90) provided for each phase of a transmission and distribution line, Phase control settling means (22) for presetting a set time (T1) and a margin time (T3) at the time of shut-off, which is the sum of the auxiliary relay operation time and the shut-off time of the switchgear, and a transmission / distribution input from the outside With respect to a plurality of current signals (I _a , I _b , I _c ) indicating current values of the respective phases of the electric wires, the relay determination time (T _RY ) or processing time (T T _PR ), the zero-point time (t _zero ) at which the amplitudes of the plurality of current signals first become zero after elapse of the total of the set time at the time of shutoff and the margin time, and the calculated zero time To current The remaining time (T) is calculated by subtracting the time, and the waiting time (T0) at the current time is calculated by subtracting the total time of the cutoff time and the margin time from the calculated remaining time. When an accident occurrence signal or an interruption instruction signal is input to the phase control determination processing means (32) to be calculated and at least one phase of the transmission / distribution line, the time when the accident occurrence signal or the interruption instruction signal is input ( wherein the calculated latency in the phase control determination processing means (T0 ₁₎ just elapsed time (t ₂₎ to t _1), blocking signal of the switching device provided on at least one phase of said transmission power distribution lines Phase control sequence processing means (42) for outputting an output signal so as to be output.
Here, according to an output signal of the phase control sequence processing means, a circuit breaker command output processing means (43) for outputting a breaking signal of a switchgear provided in at least one phase of the transmission and distribution line, and the circuit breaker command Based on the cutoff signal from the output processing means, at the time (t ₃ ) when the auxiliary relay operating time has elapsed, a switching device cutoff signal that shuts off the switching device provided in at least one phase of the transmission / distribution line is provided. An output means (52) for outputting to a shutoff circuit (91) of a switchgear provided in at least one phase of the transmission / distribution line may further be provided. When the plurality of current signals include a DC component The phase control determination processing means includes a plurality of the DC components after a lapse of time that is the sum of the relay determination time or the processing time, the cutoff time setting time, and the margin time from the current time. The zero point time when the amplitude of the current signal becomes zero first may be calculated.
The phase control determination processing means calculates an attenuation coefficient based on the direct current components of the plurality of current signals, predicts the amplitude of the direct current components of the plurality of current signals after the current time, and The amplitude of the direct current component of the current signal and the amplitude of the alternating current component of the plurality of current signals at the same time predicted based on the alternating current component of the plurality of current signals are summed, and the zero point time based on the summed amplitude May be calculated.
A sampling hold circuit (14) for sampling and holding an analog input signal at a predetermined sampling frequency, and an analog / digital converter (16) for converting the analog signal from the sampling hold circuit into a digital signal; The phase control determination processing means may calculate the zero point time, the remaining time, and the waiting time for each sampling period in the sampling hold circuit.
Only a direct current component of a plurality of analog current signals (i _a , i _b , i _c ) input from the outside or a plurality of digital current signals (I _a ) obtained by converting the plurality of analog current signals by the analog / digital converter. , I _b , I _c ) may be further provided with a low-pass filter (13) that extracts only the DC component.
When the switchgear provided for each phase of the transmission / distribution line is shut off at once, the digital protection relay device with built-in phase control outputs the output signal of the phase control sequence processing means except for three-phase failure. Based on this, the switchgear may be shut off collectively.
In the case of a one-phase failure, the phase control determination processing means calculates the zero point time, the remaining time and the waiting time for a current signal indicating the current value of the failure phase of the transmission and distribution line, and In this case, the phase control determination processing unit may calculate the zero point time, the remaining time, and the waiting time for a current signal indicating a current value of a representative phase among the faulty phases of the transmission and distribution lines.

The digital protection relay device with built-in phase control of the present invention has the following effects.
(1) It is not necessary to provide a dedicated detection / control circuit or a dedicated control device, and the phase control method can be realized by processing the input signal of the current digital protection relay device. Can also be adopted.
(2) Since the deterioration and damage of the contact portion due to the arc when the switchgear is shut off can be reduced, the inspection frequency can be reduced.

  For the above purpose, for a plurality of current signals respectively indicating the current value of each phase of the transmission / distribution line input from the outside, the relay determination time or processing time and the set time at shut-off time from the current time for each predetermined time Calculates the zero time at which the amplitude of multiple current signals first becomes zero after the elapsed time of the sum of the margin time, and calculates the remaining time by subtracting the current time from the calculated zero time. A phase control determination processing means for calculating the waiting time at the current time by subtracting the total time of the set time at shut-off and the allowance time from the remaining time, and an accident occurrence signal or cut-off for at least one phase of the transmission and distribution line When the instruction signal is input, it is the waiting time calculated in the phase control determination processing means at the time when the accident occurrence signal or the interruption instruction signal is input. By providing the digital protection relay device with a phase control sequence processing means for outputting an output signal so that a shut-off signal of the switchgear provided in at least one phase of the transmission / distribution line is output at the elapsed time It was realized.

  Embodiments of a digital protection relay device with built-in phase control according to the present invention will be described below with reference to the drawings.

  A digital protection relay device 1 with built-in phase control according to an embodiment of the present invention is used to interrupt and turn on a circuit breaker 90 that is a single-phase circuit breaker (a circuit breaker provided for each phase of a transmission and distribution line). As shown in FIG. 1, an analog input unit 10, a settling / display unit 20, an arithmetic processing unit 30, a sequence unit 40, and an input / output unit 50 are provided. The analog input unit 10, the settling / display unit 20, the arithmetic processing unit 30, the sequence unit 40, and the input / output unit 50 are connected via a bus.

  The analog input unit 10 includes an input converter 11, a band-pass filter 12 (hereinafter referred to as “BPF 12”), a low-pass filter 13 (hereinafter referred to as “LPF”), and a sampling hold circuit 14 (hereinafter referred to as “LPF”). , “S / H circuit 14”), multiplexer circuit 15 (hereinafter referred to as “MPX circuit 15”), and analog / digital converter 16 (hereinafter referred to as “A / D converter 16”). .).

The BPF 12 extracts only an AC component (for example, commercial frequency 60 Hz) of an analog signal as shown below inputted from the outside via the input converter 11.
(1) First to third analog current signals i _a , i _b , i _c indicating the current values of the a-phase, b-phase and c-phase of the transmission and distribution lines, respectively.
(2) Analog zero-phase current signal i ₀ indicating the zero-phase current value
(3) First to third analog bus voltage signals vB _a , vB _b , vB _c indicating the voltage values of the a phase, b phase, and c phase of the bus, respectively.
(4) First to third analog line voltage signals vL _a , vL _b , and vL _c indicating the voltage values of the a-phase, b-phase, and c-phase of the transmission and distribution lines, respectively.
(5) Analog line voltage signal vL indicating the voltage value of the representative phase of the transmission and distribution line
(6) Analog zero-phase voltage signal v ₀ indicating zero-phase voltage.
LPF13 extracts first to third analog current signal i _a is input via the input transducer 11 from the outside, i _b, only the DC component of the i _c.
The S / H circuit 14 samples and holds the output signal of the BPF 12 and the output signal of the LPF 13 at a predetermined sampling frequency (for example, 5760 Hz (electrical angle 3.75 ° in the case of a commercial frequency of 60 Hz)).
The MPX circuit 15 switches the output signal of the S / H circuit 14 and outputs it to the A / D converter 16.
The A / D converter 16 converts the analog signal input from the MPX circuit 15 into a digital signal.

The settling / display unit 20 includes a relay settling unit 21, a phase control settling unit 22, and a display circuit 23.
The relay settling unit 21 performs a predetermined relay settling process based on the digital zero-phase current signal I ₀ and the digital zero-phase voltage signal V ₀ input from the analog input unit 10.
The phase control setter 22 sets a cutoff time setting time T1 and a margin time T3, which will be described later.
The display circuit 23 displays the relay settling processing result in the relay settling unit 21, the cutoff time setting time T <b> 1 and the margin time T <b> 3 set in the phase control setting unit 22 on an external display device (not shown).

The arithmetic processing unit 30 includes a relay determination processing unit 31 and a phase control determination processing unit 32.
Relay determination processing unit 31 performs predetermined arithmetic processing on a digital signal (for example, digital zero-phase current signal I ₀ or digital zero-phase voltage signal V ₀ ) input from analog input unit 10.
The phase control determination processing unit 32 calculates a waiting time T0 described later for each sampling period in the S / H circuit 14 of the analog input unit 10.

The sequence unit 40 includes a relay sequence processing unit 41 (hereinafter referred to as “relay SQ processing unit 41”), a phase control sequence processing unit 42 (hereinafter referred to as “phase control SQ processing unit 42”), and an interruption. A device command output processing unit 43 (hereinafter referred to as “CB command output processing unit 43”).
The relay SQ processing unit 41 performs a predetermined sequence process based on the calculation processing result in the relay determination processing unit 31 of the calculation processing unit 30 and outputs an accident occurrence signal when the occurrence of an accident such as a ground fault or a short-circuit accident is detected. At the same time, a reclosing signal for closing the circuit breaker 90 is output after the non-voltage state for a predetermined time. The relay SQ processing unit 41 also includes an input command circuit 71 of another protection relay device or control device (hereinafter referred to as “another protection relay device / control device”) 70 or an input command circuit 81 of the monitoring control device 80. A predetermined sequence process is performed based on an input command signal input from the input circuit 51 of the input / output unit 50 through the input / output unit 50, and an input instruction signal is output. Further, the relay SQ processing unit 41 receives a turn-off command input from the turn-off command circuit 72 of another protection relay device / control device 70 or the turn-off command circuit 82 of the monitoring control device 80 via the input circuit 51 of the input / output unit 50. A predetermined sequence process is performed based on the signal, and a shut-off instruction signal is output.
When receiving the accident occurrence signal and the cutoff instruction signal from the relay SQ processing unit 41, the phase control SQ processing unit 42 receives the waiting time T0 (waiting time T0) calculated in the phase control determination processing unit 32 of the arithmetic processing unit 30 from that time. ₁ ) The output signal is output to the CB command output processing unit 43 so that the breaker signal of the breaker 90 is output after a lapse of time.
The CB command output processing unit 43 outputs the breaking signal of the circuit breaker 90 in accordance with the output signal of the phase control SQ processing unit 42, or turns on the circuit breaker 90 in accordance with the re-closing on signal or on instruction signal from the relay SQ processing unit 41. Or output a signal.

The input / output unit 50 includes an input circuit 51 and an output circuit 52.
The input circuit 51 includes an input command signal 71 from the ON command circuit 71 of the other protection relay device / control device 70 and an input command signal 71 from the input command circuit 71 of the monitoring control device 80, and an OFF command circuit 72 of the other protection relay device / control device 70. In addition, a cut command signal from the cut command circuit 82 of the monitoring control device 80 is received.
The output circuit 52 is based on the interruption signal and the closing signal from the CB command output processing unit 43 of the sequence unit 40, and after the elapse of a predetermined auxiliary relay operation time, the circuit breaker interruption signal (switching device interruption) Signal) and a breaker closing signal (switching device closing signal) for turning on the breaker 90 are output to the breaking circuit 91 and closing circuit 92 of the breaker 90, respectively.

Next, the operation of the digital protection relay device 1 with built-in phase control will be described.
First, a first analog current signal i containing no DC component due to a ground fault occurring in the a phase of the transmission and distribution line at time t ₀ (hereinafter referred to as “accident occurrence time t ₀ ”) shown in FIG. A case where _a is input will be described as an example.

  An interruption set time T1 (for example, 43 ms) that is a sum of the auxiliary relay operation time (for example, 10 ms) and the circuit breaker 90 (for example, 33 ms) shown in FIG. 2, and a margin time T3 (for example, 2 ms) Is set in advance in the phase control settling unit 22 of the settling / display unit 20.

Since the first analog current signal i _a is inputted to BPF12 and LPF13 via the input transducer 11 of the analog input unit 10, the first analog current signal i _a does not include a DC component, in FIG. 2 A first digital current signal I _a having a waveform as shown is output from the analog input unit 10.

The phase control determination processing unit 32 of the arithmetic processing unit 30 starts from the current time t (t <t ₀ ) for each sampling period in the S / H circuit 14 of the analog input unit 10 for the first digital current signal I _a. The time t _zero when the amplitude of the first digital current signal I _a first becomes zero after the sum of the relay determination time T _RY , the set time T1 at shutoff, and the margin time T3 has elapsed (hereinafter referred to as “zero time t _The residual time T (= t _zero −t) is calculated by subtracting the current time t from the calculated zero time t _zero . Further, the phase control determination processing unit 22 subtracts the total time of the cutoff time setting T1 and the allowance time T3 from the calculated remaining time T for each sampling period, so that the waiting time T0 (= T) at the current time t. -T1-T3).

Thereafter, when a ground fault occurs in the phase a of the transmission / distribution line at the accident occurrence time t ₀ , the relay SQ processing unit 41 of the sequence unit 40 is based on the calculation processing result in the relay determination processing unit 31 of the calculation processing unit 30. This ground fault is detected by performing a predetermined sequence process, and an accident occurrence signal is output at time t ₁ when the relay determination time T _{RY has} elapsed from the accident occurrence time t ₀ .

Phase control SQ processor 42 of the sequence unit 40 receives an accident occurrence signal at time t ₁ from the relay SQ unit 41, has elapsed waiting time T0 ₁ calculated in the phase control determination processing unit 32 at time t ₁ as blocking signal of the circuit breaker 90 for a phase of transmission and distribution lines at time t ₂ is output, and outputs an output signal to the CB command output processing unit 43.

The CB command output processing unit 43 of the sequence unit 40 outputs a cutoff signal of the circuit breaker 90 for the a phase of the transmission and distribution line at time t ₂ in accordance with the output signal of the phase control SQ processing unit 42.

The output circuit 52 of the input-output unit 50, based on the interruption signal from the CB command output processing section 43, the time t ₃ when has elapsed auxiliary relay operation time from time t _2, the circuit breaker interrupting signal transmission and distribution wires a It outputs to the interruption | blocking circuit 91 of the circuit breaker 90 for phases.

Thus, just before time t ₄ margin time T3 than zero time t _ZERO, disconnection of the contact portion of the circuit breaker 90 for a phase of transmission and distribution lines are completed. As a result, in the circuit breaker 90 is for disconnecting the contact portion is completed when the first analog current signal i _a mostly zero, it is possible to suppress the arc current to a minimum.

Note that the margin time T3, taking into account the variation of the cut-off time of the auxiliary relay operation time and circuit breaker 90, disconnecting the contacts of the circuit breaker 90 before the amplitude of the first analog current signal i _a becomes zero Set to ensure completion.

Furthermore, the fault is cleared time the accident occurrence time t ₀ in this case up to the accident disappearance time (= zero point time t _ZERO) is, 15 ms relay determination time, 5 ms latency T0 _1, the auxiliary relay operating time 10 ms, the circuit breaker If the interruption time of 90 is 33 ms and the margin time T3 is 2 ms, it is 65 ms (= 15 ms + 5 ms + 10 ms + 33 ms + 2 ms).

Further, the case where the waiting time T0 ₁ is maximized at time t ₁ is the case as shown in FIG. 3, the waiting time T0 ₁ at time t ₁ in this case is 1/2 cycle (commercial frequency 60Hz for commercial frequency In some cases, the accident removal time is 68 ms (= 15 ms + 8 ms + 10 ms + 33 ms + 2 ms).
Meanwhile, the case where the waiting time T0 ₁ at time t ₁ becomes the minimum is the case as shown in FIG. 4, the waiting time T0 ₁ at time t ₁ of the case is 0ms, the fault is cleared time in the example described above 60 ms (= 15 ms + 0 ms + 10 ms + 33 ms + 2 ms).

Then, if the ground fault in a phase of transmission and distribution lines are first analog current signal i _a including a direct-current component has been input in occurs at time t ₀ shown in FIG. 5 (accident occurrence time t ₀₎ The operation of the digital protective relay device 1 with built-in phase control will be described.

Although the first analog current signal i _a is input to BPF12 and LPF13 via the input transducer 11 of the analog input unit 10, since the first analog current signal i _a includes a DC component, in FIG. 5 A DC component signal and an AC component signal of the first digital current signal I _a indicated by a broken line are output from the analog input unit 10.

Phase control determination processing unit 32 of the arithmetic processing unit 30, based on the DC component signal and the AC component signal of the first digital current signal I _a, at each sampling period in the S / H circuit 14 of the analog input unit 10, the current Time t _zero (the amplitude of the first digital current signal I _a (including the direct current component) first becomes zero after the total time of the relay determination time T _RY and the shut-off set time T1 elapses from time t Zero time t _zero ) is calculated. At this time, the phase control determination processing unit 32, the DC component of the first digital current signal I _a first digital current signal I _a current time t since calculating the damping coefficient based on the DC component signal of The amplitude of the first digital current signal I _a at the same time predicted based on the predicted amplitude of the DC component of the first digital current signal I _{a and} the AC component signal of the first digital current signal I _a is predicted. The AC component amplitudes are summed, and a zero point time t _zero is calculated based on the summed amplitudes.
The phase control determination processing unit 32 calculates the remaining time T (= t _zero −t) by subtracting the current time t from the zero point time t _zero calculated as described above for each sampling period, and calculates the calculated remaining time. The waiting time T0 (= T−T1−T3) at the current time t is calculated by subtracting the total time of the set time T1 and the margin time T3 from the time T.

Thereafter, when a ground fault occurs in the phase a of the transmission / distribution line at the accident occurrence time t ₀ , the relay SQ processing unit 41 of the sequence unit 40 is based on the calculation processing result in the relay determination processing unit 31 of the calculation processing unit 30. This ground fault is detected by performing a predetermined sequence process, and an accident occurrence signal is output at time t ₁ when the relay determination time T _{RY has} elapsed from the accident occurrence time t ₀ .

Phase control SQ processor 42 of the sequence unit 40 receives an accident occurrence signal at time t ₁ from the relay SQ unit 41, has elapsed waiting time T0 ₁ calculated in the phase control determination processing unit 32 at time t ₁ as blocking signal of the circuit breaker 90 for a phase of transmission and distribution lines at time t ₂ is output, and outputs an output signal to the CB command output processing unit 43.

The CB command output processing unit 43 of the sequence unit 40 outputs a cutoff signal of the circuit breaker 90 for the a phase of the transmission and distribution line at time t ₂ in accordance with the output signal of the phase control SQ processing unit 42.

The output circuit 52 of the input-output unit 50, based on the interruption signal from the CB command output processing section 43, the time t ₃ when has elapsed auxiliary relay operation time from time t _2, the circuit breaker interrupting signal transmission and distribution wires a It outputs to the interruption | blocking circuit 91 of the circuit breaker 90 for phases.

Thus, just before time t ₄ margin time T3 than zero time t _ZERO, disconnection of the contact portion of the circuit breaker 90 for a phase of transmission and distribution lines are completed. As a result, in the circuit breaker 90 is for disconnecting the contact portion is completed when the amplitude almost zero of the first analog current signal i _a, it is possible to suppress the arc current to a minimum.

Next, at a time t ₀ (hereinafter referred to as “reception time t ₀ ”) shown in FIG. 6, a circuit breaker 90 for the a phase of the transmission / distribution line from the disconnection command circuit 72 of another protection relay device / control device 70. The operation of the digital protection relay device 1 with built-in phase control when receiving a cut command signal for shutting off the operation will be described.

Since the first analog current signal i _a is inputted to BPF12 and LPF13 via the input transducer 11 of the analog input unit 10, the first analog current signal i _a does not include a DC component, in FIG. 6 A first digital current signal I _a having a waveform as shown is output from the analog input unit 10.

Phase control determination processing unit 32 of the arithmetic processing unit 30, interrupting the first digital current signal I _a, at each sampling period in the S / H circuit 14 of the analog input unit 10, a processing time T _PR from the current time t The time t _zero (zero time t _zero ) at which the amplitude of the first digital current signal I _a first becomes zero after the total time of the time setting time T1 and the margin time T3 has elapsed is calculated, and the calculated zero time The remaining time T (= t _zero −t) is calculated by subtracting the current time t from t _zero . Further, the phase control determination processing unit 22 subtracts the total time of the cutoff time setting T1 and the allowance time T3 from the calculated remaining time T for each sampling period, so that the waiting time T0 (= T) at the current time t. -T1-T3).

The relay SQ processing unit 41 of the sequence unit 40 performs predetermined sequence processing based on a turn-off command signal from the turn-off command circuit 72 of another protective relay device / control device 70 received via the input circuit 51 of the input / output unit 51. To output a shut-off instruction signal. This shut-off instruction signal is output from the relay SQ processing unit 41 at time t ₁ when the processing time T _{PR has} elapsed from the reception time t ₀ at which this turn-off command signal is received.

Phase control SQ processor 42 of the sequence unit 40 receives the blocking instruction signal from the relay SQ processor 41 at time t _1, has elapsed waiting time T0 ₁ calculated in the phase control determination processing unit 32 at time t ₁ as blocking signal of the circuit breaker 90 for a phase of transmission and distribution lines at time t ₂ is output, and outputs an output signal to the CB command output processing unit 43.

The CB command output processing unit 43 of the sequence unit 40 outputs a cutoff signal of the circuit breaker 90 for the a phase of the transmission and distribution line at time t ₂ in accordance with the output signal of the phase control SQ processing unit 42.

The output circuit 52 of the input-output unit 50, based on the interruption signal from the CB command output processing section 43, the time t ₃ when has elapsed auxiliary relay operation time from time t _2, the circuit breaker interrupting signal transmission and distribution wires a It outputs to the interruption | blocking circuit 91 of the circuit breaker 90 for phases.

Thus, disconnection of the contact portion of the circuit breaker 90 for a phase of transmission and distribution lines are completed only before time t ₄ margin time T3 than zero time t _ZERO. As a result, in the circuit breaker 90 is for disconnecting the contact portion is completed when the amplitude almost zero of the first analog current signal i _a, it is possible to suppress the arc current to a minimum.

  Note that the digital protection relay device 1 with built-in phase control operates in the same manner even when a turn command signal is received from the turn command circuit 82 of the monitoring control device 80.

  The operation of the digital protection relay device 1 with built-in phase control in the case where the circuit breaker 90 for the a phase of the transmission / distribution line is interrupted has been described above, but any one of the a phase, b phase, and c phase of the transmission / distribution line is described. Even in the case where the circuit breaker 90 for each phase is disconnected for the phases or more, the digital protective relay device 1 with built-in phase control performs the same operation for each phase of the power transmission and distribution line.

Further, the digital protection relay device 1 with built-in phase control has been described as being used for breaking and turning on the breaker 90 that is a single-phase breaker. However, the phase control is performed on the breaker 90 that is a three-phase breaker. When the built-in digital protection relay device 1 is used, the arc current can be minimized in the same manner except for a three-phase failure.
That is, in the case of a one-phase failure, since it is a failure of only one phase, the circuit breaker 90 is shut off by performing the above-described phase control at the failure phase timing. Since the phase of the phase current is inverted by 180 °, the zero point has the same timing. Therefore, the circuit breaker 90 is blocked by performing the above-described phase control at the timing of the representative phase (for example, the leading phase) of the fault phases. By doing so, the arc current can be minimized.

  As shown in FIG. 1, the BPF 12 is provided before the sampling and holding circuit 14, but a band pass filter (BPF) formed of a digital circuit may be provided after the A / D converter 16.

  As described above, the digital protection relay device with built-in phase control according to the present invention can be used, for example, to reduce deterioration or damage of a contact portion due to an arc when a power system switching device is shut off.

It is a figure which shows the structure of the digital protection relay apparatus 1 with a built-in phase control by one Example of this invention. Phase control internal digital protection first analog current signal i _a to ground fault in a phase of transmission and distribution lines to the accident occurrence time t ₀ does not contain a DC component occurs as shown in FIG. 1 when that has been entered FIG. 6 is a diagram for explaining the operation of the relay device 1. Waiting T0 ₁ at time t ₁ is a diagram for explaining the case where the maximum. Waiting T0 ₁ at time t ₁ is a diagram for explaining a case where a minimum. First analog current signal i _a phase control internal digital protective relay shown in FIG. 1 when that has been input including a DC component ground fault occurs in a phase of transmission and distribution lines to the accident occurrence time t ₀ 4 is a diagram for explaining the operation of the device 1. FIG. Built-in phase control shown in FIG. 1 when receiving a turn-off command signal for turning off the a-phase circuit breaker 90 of the transmission / distribution line from the turn-off command circuit 72 of another protection relay device / control device 70 at the reception time t ₀ 4 is a diagram for explaining the operation of the digital protection relay device 1. FIG.

Explanation of symbols

1 Digital Protection Relay Device with Built-in Phase Control 10 Analog Input Unit 11 Input Converter
12 Bandpass filter (BPF)
13 Low pass filter (LPF)
14 Sampling hold circuit (S / H circuit)
15 Multiplexer circuit (MPX circuit)
16 Analog / digital converter (A / D converter)
20 Setting / Display Unit 21 Relay Setting Unit 22 Phase Control Setting Unit 23 Display Circuit 30 Arithmetic Processing Unit 31 Relay Determination Processing Unit 32 Phase Control Determination Processing Unit 40 Sequence Unit 41 Relay Sequence Processing Unit (Relay SQ Processing Unit)
42 Phase control sequence processing unit (phase control SQ processing unit)
43 Circuit breaker command output processing unit (CB command output processing unit)
50 Input / Output Unit 51 Input Circuit 52 Output Circuit 70 Other Protection Relay Device / Control Device 71 On / Off Command Circuit 72 Off Command Circuit 80 Monitoring Control Device 81 On / Off Command Circuit 82 Off Command Circuit 90 Breaker 91 Break Circuit 92 Closing Circuit I _a ~I _c first through third digital current signal T remaining time T0 ₁ wait T1 at intercepting the set time T3 margin time T _RY relay judgment time T _PR processing time t ₀ ~t _4, t _zero time

Claims (8)

A digital protection relay device with built-in phase control (1) used to shut off and turn on a switching device (90) provided for each phase of a power transmission and distribution line,
A phase control settling means (22) for setting in advance a set time (T1) and a margin time (T3) at the time of shutoff, which is a sum of the auxiliary relay operation time and the shutoff time of the switchgear;
With respect to a plurality of current signals (I _a , I _b , I _c ) respectively indicating the current values of each phase of the transmission / distribution line inputted from the outside, the relay determination time ( T _RY ) or processing time (T _PR ), and the zero point time (t _zero ) at which the amplitudes of the plurality of current signals first become zero after elapse of the sum of the set time at shut-off time and the margin time, respectively. Then, the remaining time (T) is calculated by subtracting the current time from the calculated zero point time, and the current time is obtained by subtracting the total time of the shut-off set time and the margin time from the calculated remaining time. Phase control determination processing means (32) for respectively calculating the waiting time (T0) at the time of
When an accident occurrence signal or an interruption instruction signal is input for at least one phase of the transmission and distribution line, the phase control determination processing means calculates at the time (t ₁ ) when the accident occurrence signal or the interruption instruction signal is input. Phase control for outputting an output signal so that a shut-off signal of a switchgear provided in at least one phase of the power transmission / distribution line is output at a time (t ₂ ) when the set waiting time (T 0 ₁ ) has elapsed Sequence processing means (42);
A digital protection relay device with a built-in phase control, comprising: According to the output signal of the phase control sequence processing means, a circuit breaker command output processing means (43) for outputting a shut-off signal of a switchgear provided in at least one phase of the transmission and distribution line;
Based on the interruption signal from the circuit breaker command output processing means, at the time (t ₃ ) when the auxiliary relay operation time has elapsed, the opening / closing operation that shuts off the switching device provided in at least one phase of the transmission / distribution line Output means (52) for outputting a device shut-off signal to a shut-off circuit (91) of a switchgear provided in at least one phase of the transmission and distribution line;
The digital protection relay device with built-in phase control according to claim 1, further comprising:   When the plurality of current signals include a direct current component, the phase control determination processing means has elapsed from the current time by adding the relay determination time or the processing time, the cutoff time setting time, and the margin time. 3. The digital protection relay device with built-in phase control according to claim 1, wherein the zero point times when the amplitudes of the plurality of current signals including the direct current component are initially zero are respectively calculated later.   The phase control determination processing means calculates an attenuation coefficient based on the direct current components of the plurality of current signals, predicts the amplitude of the direct current components of the plurality of current signals after the current time, and The amplitude of the direct current component of the current signal and the amplitude of the alternating current component of the plurality of current signals at the same time predicted based on the alternating current component of the plurality of current signals are summed, and the zero point time based on the summed amplitude The digital protection relay device with built-in phase control according to claim 3, wherein: A sampling and holding circuit (14) for sampling and holding an analog input signal at a predetermined sampling frequency;
An analog / digital converter (16) for converting an analog signal from the sampling and holding circuit into a digital signal;
5. The phase control built-in according to claim 1, wherein the phase control determination processing unit calculates the zero time, the remaining time, and the waiting time for each sampling period in the sampling hold circuit. Digital protection relay device. Only a direct current component of a plurality of analog current signals (i _a , i _b , i _c ) input from the outside or a plurality of digital current signals (I _a ) obtained by converting the plurality of analog current signals by the analog / digital converter. , I _b, characterized by further comprising a low-pass filter for extracting only the DC component of the I _c) (13), the phase control internal digital protection relay device according to claim 5.   When the switchgear provided for each phase of the transmission / distribution line is shut off at once, the digital protection relay device with built-in phase control outputs the output signal of the phase control sequence processing means except for three-phase failure. The digital protection relay device with a built-in phase control according to any one of claims 1 to 7, wherein the switchgears are collectively shut off based on the switching device. In the case of a one-phase failure, the phase control determination processing means calculates the zero point time, the remaining time and the waiting time for a current signal indicating the current value of the failure phase of the transmission and distribution line,
In the case of a two-phase failure, the phase control determination processing means calculates the zero point time, the remaining time, and the waiting time for a current signal indicating a current value of a representative phase among the failed phases of the transmission and distribution lines. ,
The digital protection relay device with built-in phase control according to claim 7, wherein:

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